Biological adjusting cling film was used to wrap yam and garlic in the experiment. Microorganism growth would be inhibited by the anti-microbial activity of garlic during the storage. The aim of the experiment was to research the preservation effect of yam in room temperature. Many experimental parameters were measured such as weight loss ratio, microorganism, VC, sugar content and hardness. It was found the garlic caused significant antibacterial activities after observation, date measuring and analyzing. It could also help reduce the weight loss ratio, while the decreases in sugar content, VC and hardness were slowed down, hence shelf life of yam was prolonged. Through yam and garlic proportion experiments, it was found by adding 3 to 4 pieces(about 4 to 5 g) garlic into fresh packaging of 150 g yam, the optimal anti- microbial effect was achieved.